Air preheater



April 13 ,1926.

` Imm/rm FII Mmmm-:-

Patented. Apr. 1*.3, l192.6.

vri-simeri. ammonia, or krengffi Ara rnnmurnaf .espumas inea member9,1921.; serial its.: 521,246.

To all whom z'timay concern."

Be it' known that I, VIK'roR lRnrnaonn, a.

German citizen, residing at Kiel, in the German Republic, have inventednew and useful Improvements in an Air Preheater,

of which the following is a specification.-

This invention relates to internal combustion engines. The hightemperatures obtaining in the cylinders of "such enginescauses theinternal walls of the'cylinders to be highly heated, while the outersurfaces of the cylinders are greatly cooled down by'air or watercurrent. This condi# tion produces in the interior of the walls of thecylinders such high stresses that often V l,the material crystallizesand deteriorates.

This destructive action is greatly increased in reversible motors, suchfor example as ships motors when the cold air introduced into thecylinders suddenly cools the hot walls of the cylinders.

It is common knowledge that in reversible ships motors, the walls of thecylinders often become cracked and then render -1m` possible any normalworking condition ory service.

The present object is to heat the starting air before its introductioninto the cylinder. As in first starting the engine the cylinders arestill cold and the said objections do not obtain, the heating of the airsupply for` the cylinders is only then necessary when, during coldweather, the temperature within the cylinders is to be raised for thepurpose of facilitating ignition.

It is usual to heat the gas mixture by means of a heat storer connectedwith the exhaust conduit. It also -is known in some instances to heatthe air supply for internal combustion motors. The present object is andthe noveltyl of the invention consists in the provision of a heat storermounted on the exhaust pipe `of and in promixity to'each engine cylinderfor heating the air supply provided ,for the starting of the me. heinvention is shown in the accompanying` drawings, in which: s

f igure 1 is a vertical central section through a heat storer of thekind described; Figure 2 is a development showing the alr passage;Figure 3 isa horizontal cross sectional viewA of the heat storer and Fi4 is a plan showing the invention Aapplic to a four cylinder engine byway of example.

. disposed tube nels c surrounding the tubular portion .b 4and.

-. i he hcatstorer o: comprises acentrally p rtio'n b forming part ofthe exhaust-pipe romeach motor cylindenso that*l ftheexhaust `gases passimmediately through the dpipe 'b which yquickly becomes highly heate tothe temperature of thexexhaust gases and then passes the heat to the`surrounding pipes. The heat storer'j al1-1s surrounded. by a spacedycasing m which leaves an annular space d forming a.` dead enters by cand circulates through the-chanleaves at f in a'hot condition. Thechannels w a air space for preventing the loss of heat from theinterior. The air supply to" be heated c are shown in Fig. 2 in a planeof develop ment.

'If it is desired to heat the airl supply forfk i the starting of theengine whilst the cylmder walls are still cold, arrangement is made forheating the heat storer a by steam1-for1 example, by introducing theheating mediuln through a socket i1. into the annular s ace df) anddischarging same through a ysoc et-g. i'

Any other means for -heating same may be adopted.

It is .of greatimportance to have the heat storer as close as possibleto the outlet of the exhaust gas in each engine cylinder, because thegas is. hottest at that point. Fig. 4 shows how this can be carried outby directly fixing the flange of the tube b direct onto the motorcylinder a' and connecting the outlet from the storer with the'exhaustchamber a.

Each cylinder z' of a multi-c linder nmotor is provided with an inletvave la and an outlet valvel Z. The tube connection n leads from thestarting valve c to the heat storer a. The compressed air pi e p isconnected with each yinletl e of the eat storers a soA that the heatedair leaving at f flowsthrough fn. and le into the correspondincylinder.- In

placing* the heat storer a c osely 'to each cylinder z' a furtheradvantage is obtainedv in that the pipe connection n for the hot airsupply is reduced as far as possible and prevents the loss of heat.

Further, it is of importance. to choose an adequately proportionedheating surface' for the heatstorer with reference to the heatdischarging surface containing the starting air supply for thecylinders. The surface for absorbing the heat.J should, therefore,

not be too large in comparison with the 110 umr surface serving indistributing the heat to the circulating air supply, because in shuttin`down the motor the air, sucked in by eac cylinder z', receives nolonger'any fresh t I claim: y An air reheater comprising a body portionprovi ed with a central passage through which/the exhaust gases areadapted to a-ss, an .annular passage formed in the wa l of said bodyportion around said central passage through which the air to be heatedis ada ted to pass, and a chamber surrounding sai annular passag adaptedto receive a heating fluid and ing spaced therefrom by a wall of heattransmitting material, said wall being the bodyportion of said prelheater.

VIK'roRA REMBOLD j

